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The appearance of gemstones can be enhanced by treatment to improve color, clarity, durability etc. This may be done to produce new colors, to improve the original color and shine of a gemstone, to improve clarity of gemstones, to reduce porosity in gemstones and even to stabilize color or to enhance durability. Usually each stone requires different treatment to be done. The difference could be in the type of treatment applied or the intensity of the treatment. Such alteration could be easy as well as impossible to detect.
In global business, it is never advisable to sell any artificially enhanced gems without full disclosure of information about the treatment. Unfortunately, full disclosure is an exception rather than the rule in the marketplace.
Let us have a quick view of the frequently used methods and treatments for gem enhancements.
Heat Treatment
Heat Treatment of a Gem means heating a gem under controlled conditions. Routine heating under controlled conditions of gems like aquamarine, Sapphire, Ruby, Tourmaline often improves the gem in its color. However gems like sapphire, amethyst, citrine, topaz and zircon are heated to alter their color. In the mean time, in gems like Sapphire and Ruby, heat treatment could be effective in improving clarity. Since lot many gems under go natural heating (e.g., in volcanic areas, or in hot steam areas), sometimes the artificial effects become indistinguishable from natural effects. In majority of the cases, the results of heat treatment are permanent.
Irradiation
Irradiation of a Gem means exposing a gemstone under controlled conditions to radiations. Irradiation is capable of producing a wide variety of colors of yellowish diamonds. Some color stones, for example topaz is irradiated in large quantities and then heat treated to produce various shades of blue. Even Tourmaline can be irradiated to enhance or produce new colors. However in many cases, the effects of irradiation are somewhat unstable and can be reversed by heating.
Chemical Treatment and Impregnation
Treating Gemstones chemically can produce superb results in in enhancing colors or even in producing new colors. To stabilize porous Turquoise and improve its color, Turquoise and improve resin. Diamonds with a yellow tint are coated on girdle or pavilion with thin bluish film to produce brilliant colors. Chemical bleach and impregnation improve Jadeite's color. For stones like "Black Onyx", impregnation and carbonization by acid is usually practiced. Dull corundum can be enhanced by heating it in chemicals to get a thin layer of color deposited on stone's surface. Chemical treatment results in impressive colors but colors may not last when stones are recut.
Assembled Stones
Roughly assembled stones means using a combination of gemstones to increase improve their looks. For example the play of colors in gemstones can be enhanced by use of dark backing such as in quarts. Quarts top imparts more durability and stability. Thin seams of opal stones are assembled with opal or black onyx backing producing a doublet, a clear Quartz top added to it produces a triplet. However, opal doublets and triplets must be taken care of against heat and liquids.
Although gemstone cutting is the most basic enhancement method necessary to fully display the beauty of a gemstone, there are many fascinating methods by which humans have demonstrated theirability to draw maximum color, luster, clarity and brilliance from nature's earthbound treasures. A basic understanding of these enhancement techniques will add to your appreciation of the beauty, durability and value of the gemstone jewelry you already own, or purchase now and in the future.
Below are some gem enhancement techniques used for
some of the gemstones.
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